Process development for the catalytic oxidation of hydrogen chloride in a two-stage fluidized bed reactor

A worldwide environmental waste disposal concern in the chemical industry is the handling of hydrochloric acid by-product. Hydrochloric acid results from the use of chlorine in many chemical processes. In recent years there has been an increased production of chlorinated hydrocarbons, which has resulted in the production of large quantities of hydrochloric acid. Because of the hazards surrounding hydrochloric acid there is an increased interest in the development of a safe and economic process for the recovery of chlorine from hydrogen chloride. A new two-stage process has been studied in order to carry out the catalytic oxidation of hydrogen chloride to produce chlorine for recycle. This catalytic oxidation process combines two stages: In the first stage, consisting of a fluidized bed operating at a temperature in the range of 340 to 400°C, the exothermic oxidation of hydrogen chloride to produce chlorine is carried out. The catalyst from this high temperature exothermic reactor is then transported to a second reactor which operates at a temperature in the range of 180 to 200°C. In this reactor all of the unconverted hydrogen chloride in the overhead gas from the first reactor is reacted, yielding a stream of chlorine, residual oxygen and nitrogen along with water vapor which passes into a recovery system. This new two-stage process can essentially provide 100% conversion of hydrogen chloride to chlorine in a safe and economic manner. This gives a novel solution to the problem of hydrochloric acid disposal.